Editing Cape Cod Bay (section)

==Geology==
Most of Cape Cod is composed of glacially derived rocks, sands, and gravels. The [[last glacial period]] ended about 12,000 years ago. During the end of the last glaciation, Cape Cod Bay was probably a large freshwater lake with drainages across Cape Cod in places like [[Bass River (Massachusetts)|Bass River]] and Orleans Harbor. The Provincetown Spit, i.e., the land north of High Head in [[North Truro, Massachusetts|North Truro]], was formed by marine deposits over the last 5,000-8,000 years. These deposits created [[Provincetown Harbor]], a large, bowl-shaped section of Cape Cod Bay. Generally, currents in the Bay move in a counter-clockwise fashion, moving south from [[Boston, Massachusetts|Boston]], to [[Plymouth, Massachusetts|Plymouth]] then east and then north to [[Provincetown, Massachusetts|Provincetown]]. Strong tides flow water into the Bay, cleansing the system with nutrient-rich sea water and maintaining a well-mixed marine environment that helps to maintain a generally healthy and productive system by exchanging roughly 9.3% of the total bay water volume on a regular basis.<ref name="coastalstudies.org">{{Cite web |title=Cape Cod Bay {{!}} Center for Coastal Studies |url=https://coastalstudies.org/cape-cod-bay/#:~:text=Cape |access-date=2022-05-04 |website=coastalstudies.org |archive-date=2021-06-02 |archive-url=https://web.archive.org/web/20210602215223/https://coastalstudies.org/cape-cod-bay/#:~:text=Cape |url-status=live }}</ref> Surface water stratification and mixing have a distinct seasonal cycle in the Bay. In the winter, the density of bay water is nearly the same from top to bottom, allowing it to mix readily and become nutrient-rich all around. Stratification occurs when the surface water becomes warmer and less thick than the deeper water in the spring, summer, and early fall.<ref name="coastalstudies.org"/> Because the water is stratified and rich in nutrients in the spring, biological productivity in the bay is at its peak.<ref name="coastalstudies.org"/>

Since 1914, Cape Cod Bay has been connected to [[Buzzards Bay (bay)|Buzzards Bay]] by the [[Cape Cod Canal]], which divides the upper cape towns of Bourne and Sandwich.